cryptfs: Remove dm-crypt device on failed table load

 * The dm-crypt device needs to be removed from
   the device-mapper driver list otherwise it will
   remain busy and cannot be used later on by
   other processes (eg vold_decrypt) or for further
   testing/debugging in recovery.

Change-Id: I35e43a79ecc3de234ddb9f87f7d75c6439ea7454